Cycle defrost type refrigerators



p 1957 SI J. WILLIAMS, JR 2,807,149

cycps DEFROST TYPE REFRIGERATORS Filed July 15, 1955 3 Sheets-Sheet 1 p 24, 1957 sl J. WILLIAMS, JR 2,807,149

" Wm WWW P 24, 1957 SI J. WILLIAMS, JR 2,807,149

CYCLE DEFROST TYPE REFRIGERATORS Filed July 15, 1955 3 Sheets-Sheet 3 CONDENSER DISCHARGE LINE PRE-COOLER I INVENTORQ 2,807 ,149 CYCLE DEFROST TYPE REFRIGERATORS Application July 15, 1955, Serial No. 522,265 2 Claims. (Cl. 624) The present invention relates to cycle defrost type refrigerators, and is particularly concerned with the provision of an improved tion.

One of the objects of the invention is the provision of an improved household refrigerator of the class described, having an improved air air temperature recovery. 7

Another object of the invention is the provision of an improved household refrigerator of the class described, having a simple construction which is adapted to be manufactured at a low cost and to give service for a long time without necessity for repair or service.

Another object of the invention is the provision of an improved household refrigerator of the class described, which is simple in construction but which is also adapted to insure crisper and meat pan temperatures which are adequately cold and also to provide a quick chill compartment.

Another object of the invention is the provision of an improved cycle defrost refrigerator in which the evaporator surfaces which are defrosted are vertical to facilitate'quick draining of the defrost water; and in which the defrosting evaporator has part of its surfaces extended forward into the food storage compartment, so that cabinet air circulation by convection currents w-ill be im- :proved.v

Other objects and advantages of the invention will be apparent from the following description and accompanying drawings, in which similar characters of reference indicate similar parts throughout the several views.

Referring to the three sheets of drawings accompanying the specification,

Fig. 1 is a view in perspective showing the front of the cabinet with the door open;

Fig. 2 is a developed plan view of the evaporator;

Fig. 3 is a diagrammatic view in perspective showing a modified form of evaporator;

Fig. 4 is a similar view of another modified form;

Fig. 5 is a similar vie-w of another modified form;

Fig. 6 is a similar view of another modified form;

Fig. 7 is a similar view of another modified form;

Fig. 8 is a diagrammatic illustration of the refrigeration system.

Referring to Fig. is indicated in its entirety prises an insulated cabinet 21, ing closedby an insulated door 22.

The insulated cabinet may be formed by means of an insulated shell, having a bottom panel 24, secured to a pair of side panels 25, which are integrally secured by easy bends at 26 to the integral top panel 27.

The back of the cabinet is closed by a rear panel, and the front of the cabinet has the inwardly extending face flange 28 extending all about the door opening for engagement with the resilient door seal 29, carried by door 22.

The door comprises an outer stamped metal shell 30,

l, the present household refrigerator by the numeral 20, and it comhaving a front door openhousehold refrigerator construc- States Patet P tented Sept. 24, 1957 has a suitable cavity at its lower rear corner for receiving the motor compressor 33, which is located partly inside the shell'and partly outside.

The inside of the cabinet is formed by a sheet metal liner 34, having a pair of side walls 35, a rear wall 36,

. bottom wall 37, top wall 38, and a diagonal wall 39 at circulation and cabinet I the rear bottom for providing motor compressor room.

The liner has a drain opening 40 in its bottom wall which slopes toward said opening, which is adapted to drain to a drain pan 41, having its guide flanges 42 carried by guides 43 on the bottom panel.

A drain pan 41 is spaced from the bottom panel 24 to provide a clearance 44 for circulation of air over the condensate in the pan 41. The space between the liner 34 and the shell 23 is filled with suitable insulation, such as glass wool contained in plastic waterproof bags for maintaining it in a dry condition.

The liner has an outwardly extending flange 45 about the door opening adjacent the face flange 28 of the shell, and the space between these flanges is closed by an insulating breaker strip structure 46.

The cabinet is separated into an upper frozen food space 47 and a lower unfrozen food space 48 by an insulating partition 49, which may comprise a suitable plate of insulating material separated from the upper evaporator 50 by insulation 51, all carried by the liner walls.

The upper evaporator 50 may comprise a box-like sheet metal member of aluminum having bottom wall 52, top wall 53, side walls 54, and 55, and a rear wall 56. The side walls are provided with a front facing flange 57, extending all the way about the front door opening, which is closed by an insulated door 58, comprising front boxlike panel 59 of metal or plastic, and a rear plastic panel 60, secured together and filled with insulation and hinged at its lateral edge 61.

All the hinges on the doors of the ably located on the same side, which happens to be the right side in Fig. 1.

The evaporator 50 is a freezing evaporator for mainfood at a low temperature, preferably around zero degrees F., or lower; and this temperature is maintained constantly in spite of the fluctuations in temperature of the defrosting evaporator, further to be described.

The freezing evaporator 57 may be provided with sinuous coils 62 of tubing located and extending sinuously across the top 53, down the side wall 54, across the bottom 52, up the side wall 55, and across the rear wall 56, refrigerating the freezer evaporator 50 on all sides except the front.

-In addition the side wall 55 carries an accumulator 63, comprising a tubular member of larger size, sloping upwardly toward its suction discharge end 64, and in heat exchange relation to the evaporator wall 55.

The sinuous tubing and accumulator are all arranged on the outside of evaporator 50 in the insulation, which may comprise a glass wool packed in polyethylene bags, to keep the insulation dry, and the insulation and bags embedding the coils and accumulator.

The lower unfrozen food compartment preferably contains evaporator 65, which may be one of the types shown in Figs. 2 to 7, but'is preferably of the shape and arrangement shown in Fig. 1.

This is a frosting and defrosting evaporator, which is cabinet are prefer-- to a suitable temperature, such as, for example, 40 degrees F., while the upper freezer temperature may be maintained between 3 to degrees F. by its evaporator, which is, of course, cooler than the air in the evaporator.

The evaporator 65 preferably comprises a single integral aluminum plate, which has two flat parts 66 and 67 extending at right angles to each other, and both extending vertically in the compartment.

The plates 66 and 67 form part of a box-like compartnient 68, which has a top wall 69, a bottom wall 70, and a side wall 71, adjacent the liner, completing the chilling compartment 68, which has a front door opening closed by a double-walled insulating door, such as that described with respect to the evaporator 50, hinged on the right and having a door seal engaging an inwardly extending face flange 72. Both evaporators preferably have sealed and insulated doors, or drawer facings. V

The evaporator 65 is shown as a flat plate in developed form in Fig. 2, before it is bent along the line A-A, to provide the rear wall portion 66 and the side wall portion 67 of this evaporator. This evaporator is provided on its inside with sinuous coils 73, which may comprise a downwardly extending pass 74, horizontal pass 75, joined by upwardly extending portion 76 to a second horizontal pass 77. v

This is joined by upwardly extending portion 78 to a horizontal pass 79, which extends to an upwardly extending portion 80 and the fourth horizontal pass 81, leading to the outlet 82, the inlet being indicated at 83.

The line AA in Fig. 2 indicates the point at which the evaporator sheet 66 would be bent to show the shape shown in Fig. 3. The two lines BB and B'-B' indicate the points at which the evaporator sheet is bent to form the shape shown in Fig. 4.

The tubing for both evaporators is preferably of the type having an integral, longitudinally extending radial fin which is Welded or brazed to the aluminum plate, holding the tube itself in spaced relation to the plate while maintaining heat exchanging engagement with the plate.

The chilling compartment 68 may contain a plurality of drawers used for a crisper, a meat pan, and a quick chill compartment.

Referring to Figs. 3 to 7, these disclose alternative forms of defrosting evaporators. For example, Fig. 3 shows diagrammatically an L-shaped defrostnig evaporator 84, having a bottom wall 85 and a vertical wall 86.

Fig. 4 shows a U-shaped rectangular evaporator 87, having a bottom 88 and two upwardly extending walls 90.

Fig. 5 shows an evaporator 91 in the form of a full transverse partition extending across the liner and having a pair of upwardly extending side walls 92, 93.

Fig. 6 shows a transverse metallic partition 94 support ing a horizontal U-shaped evaporator 95, which has a rear wall 96 and two side walls 97 and 98.

Fig. 7 shows an L-shaped evaporator 99, having a rear' wall 100 and a side wall 101, forming part of a box-like compartment provided with three drawers 102, 103, 104, used for a lower crisper, an intermediate meat pan, and an upper quick chill compartment.

The refrigeration system is shown in Fig. 8, and this comprises a sealed motor compressor 33, including the compressor 105, located in an oil sump 106.

The outlet for the compressor is at 107, and the compressed refrigerant vapor is carried away by the tube 108, leading to one or more passes of a wire condenser 109, which passes 110 may form the precooler.

The compressor 105 has an oil inlet 111 in the sump leading to the compressor inlet and providing a constant source of oil for lubricating the compressor and motor, and the compressor pumps both refrigerant and lubricant to the precooler 110. Refrigerant returns from precooler 110 through tube 112 to the top of the motor housing 113, and the refrigerant has been partially condensed and cooled, so that it is cooler than the motor parts over which the condensed refrigerant trickles, and the oil droplets run down over the motor parts to the sump 106, effecting oil separation.

The interior of the motor housing 113 is under pressure from the compressed refrigerant, which aids in effecting lubrication of the compressor and motor by forcing lubricant into conduit 111 into the compressor.

The compressor refrigerant goes out of the motor housing 113 into tube 114, which leads to a multiplicity of passes forming the main condenser 115. Main condenser 115 and precooler 110 may all be in heat conducting relation to the same or different sets of heat radiating wires 116.

In the main condenser the refrigerant is condensed to liquid form by the removal of heat of vaporization. The main compressor outlet 117 extends to a drier capsule 118 containing screens 119 and a supply of silica gel which absorbs any water vapor which may exist in the system.

From the drier 118 a capillary tube 120 extends, and is arranged with a portion of its length 121 in heat conducting relation with the suction tube 122. The capillary tube may have a suitable coiled portion 123 for increasing its length and providing a suitable restriction for regulating the flow of liquid refrigerant, and the capillary tube extends to the inlet 124 of the freezer evaporator 62.

From the outlet of the freezer evaporator 62 a tube 125 extends downward to the inlet 83 of the defrosting evaporator plate. The outlet of the defrosting evaporator plate is at 82 and extends back to the accumulator 63, which is actually located on the freezer evaporator 62, as shown in Fig. 1.

From the accumulator the vaporized refrigerant goes back to the compressor inlet 126 through the suction line 122.

The operation of the motor compressor is controlled by a cold control switch 127, having a bellows 128 connected by capillary tube 129 to a bulb 130, and filled with a suitable volatile element, such as a refrigerant.

The bulb 130 is located in intimate heat exchange relation with the defrosting evaporator plate 73, and the cold control has a suitable range of adjustment so that it may beadjusted to turn off the motor compressor when the defrosting evaporator 73 attains a temperature of 30 degrees F., below the freezing point, and to turn on the compressor when the defrosting evaporator 73 attains a warm temperature of, for example 34 degrees F.

The range of temperature changes of the defrosting evaporator 73 should be sutficient so that this evaporator gathers frost from the humidity in the air in the abovefreezing storage compartment 48 on the outside quickchill compartment 68, the inside being closed by a sealed door or sealed drawer facings, .and containing a minimum amount of moisture in the air thereof The condensate which melts off the exterior of the defrosting evaporator compartment 65 is collected in a trough and drained by a tube through the back of the liner to the drain pan 41, where it is evaporated.

The present construction of the refrigerator may have its plate evaporator 65 provided with an electric heater which is connected in circuit when the compressor is off, and this heater aids in warming up the evaporator plate 65 during the defrosting period and speeding up the defrosting operation before contents can become warmed in any substantial amount.

The electric heater is indicated at in Fig. 8 attached to the evaporator plate 73 and connected by conductor 136 to acontact 137 and by conductor 138 to line at 139. The other line 140 is connected to the bellows actuated switch arm 141 which opens the contact 137 when the bellows 1'28 warms up. The other contact 127 is connected by conductor 142 to the motor compressor 33.

Thus the cold control bellows 128 opens the motor circuit at 127 when the evaporator becomes cold, and closes the circuit at 127 to the compressor when the evaporator becomes warm.

110 F. ambient 70 F. ambient On Off Av. On Off Av Cab. av., F 43.0 41.7 42. 3 37. 4 36. 5 37.0 Evap. temp, F -2. 6 5.2 3.3 2.3 --4.0 2.6 Chiller (compt.),

F 37. 6 35. 5 36. 6 33. 5 30.8 32.1 Meat pan, F 38 38.1 38. 33.0 32. 8 32.9 Control bulb, 37. 6. 3 37. 4. 0+ Cycle time, min. 34 16 15% 25% It will thus be observed that the present refrigerator construction provides a satisfactory meat pan temperature, and crisper and quick chill compartment temperatures. I

The present above-freezing food storage evaporator is automatically defrosted, regulating the humidity of that compartment and removing unnecessary moisture, and an improved air circulation is efiected because of the increased amount of vertical surface in contact with the air in the compartment.

While I have illustrated a preferred embodiment of my invention, many modifications may parting from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myself of all changes within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:

1. A household refrigerator of the multiple temperature type comprising an outer shell, an inner liner, insulation between said shell and liner, and breaker strips closing the space between the liner and shell surrounding a door opening, a door having a door seal for closing said opening, a separate freezer compartment comprising a second inner liner defining a box-like compartment at the top of the cabinet, sinuous coils covering the walls of said box-like compartment, which has a front door opening, an insulated cover for closing said latter front door opening,

insulation between the first liner and the second liner,

and also forming an insulating partition below said second liner, said partition forming the upper wall of a food storage compartment, a receiver carried by said second liner on its side wall, and connected to a suction line, a cycle defrost evaporator comprising a separate box-like container spaced from said first liner and located below said second liner inside said first liner, said box-like container having a side vertical wall and a rear vertical wall provided with a plurality of sinuous passes of refrigerant for cooling said vertical walls to provide a quick freeze compartment inside said box-like container and for cooling the compartment in hich it is located, for storage of food above freezmg, the refrigerant passing first to the be made without dethe energization of a motor compressor,

sinuous coils of the upper freezer liner and thereafter to the sinuous coils of said box-like container, and thereafter back to said receiver on said freezer evaporator, and a cold control switch controlling the energization of a motor compressor, and having its bulb located on said cycle defrost evaporator, and adapted to control the temperature of the latter within a range which extends below. freezing and extends to above freezing, for effecting defrost on the off cycle of said compressor, the said box-like container having drawers, one of which is adapted to serve as a chiller compartment, another which serves as a meat pan, and a third one which serves as a crisper.

2. A household refrigerator of the multiple temperature type comprising an outer shell, an inner liner, insulation between said shell and liner, and breaker strips closing the space between the liner and shell surrounding a door opening, a door having a door seal for closing said opening, a separate freezer compartment comprising a second inner liner defining a box-like compartment at the top of the cabinet, sinuous coils covering the walls of said box-like compartment, which has a front door opening, an insulated cover for closing said latter front door opening, insulation between the first liner and the second liner, and also forming an insulating partition below said second liner, said partition forming the upper wall of a food storage compartment, a receiver carried by said second liner on its side wall, and connected to a suction line, a cycle defrost evaporator comprising a separate box-like container spaced from said first liner and located below said second liner inside said first liner, said box-like container having a side vertical wall and a rear vertical wall provided with a plurality of sinuous passes of refrigerant for cooling said vertical walls to provide a quick freeze compartment inside said box-like container and for cooling the compartment in which it is located, for storage of food above freezing, ant passing first to the sinuous coils of the upper freezer liner and thereafter to the sinuous coils of said box-like container, and thereafter back to said receiver on said freezer evaporator, and a cold control switch controlling and having its bulb located on said cycle defrost evaporator, and adapted to control the temperature of the latter within a range which extends below freezing and extends to above freezing, for effecting defrost on pressor, the said box-like container having drawers, one of which is adapted to serve as a chiller compartment, another which serves as a meat pan, and a third one which serves as a crisper, and an electric heater carried by said box-like container and connected in circuit when the compressor is off, for speeding the defrosting operation of said box-like container.

References Cited in the file of this patent UNITED STATES PATENTS Jacobs et al the refrigerthe off cycle of said com 

